package jdbc;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Scanner;

/**
 * 用户登录功能
 *
 * 程序启动后，要求用户在控制台上输入用户名和密码
 * 用该用户名和密码做为过滤条件去user表中查询对应记录
 * 如果查询到记录则表示登录信息与曾经注册时输入的信息一致，那么登录成功
 * 否则登录失败
 *
 * SELECT id,username,password,nickname,age
 * FROM user
 * WHERE username='用户输入的用户名' AND password='用户输入的密码'
 *
 */
public class LoginDemo {
    public static void main(String[] args) {
        System.out.println("欢迎登录");
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入用户名:");
        String username = scanner.nextLine();
        System.out.println("请输入密码:");
        String password = scanner.nextLine();

        try (Connection connection = DBUtil.getConnection();){
            Statement statement = connection.createStatement();
            String sql = "SELECT id,username,password,nickname,age " +
                         "FROM user " +
                         "WHERE username='"+username+"' AND password='"+password+"'";

            System.out.println(sql);

            ResultSet rs = statement.executeQuery(sql);
            if(rs.next()){
                System.out.println("登录成功!");
            }else{
                System.out.println("登录失败!");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}








